What do you want to use the permeate for? And were can you send the reject?
1. Call someone who has experience designing these systems. An off the self R.O. system from Siemens/GE/Aquatech can be headaches down the road. In dairy plants organics will be your main problem and you will be...
purchase a book called Steam 41 from babcock & wilcox. Read that and formulate questions based off of what you feel is important. Your water treatment vendor should also provide training.